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Keloid scarring is an abnormal scar disease characterised by excessive proliferation of fibroblasts and over-deposition of collagen during wound healing. Although various treatments for keloid scars have been developed, preventive medicine is believed to be a promising strategy. The skin barrier limits the gentle topical administration of medicaments such as creams and hydrogel dressings, resulting in reduced therapeutic efficacy. In recent years, microneedles (MNs) have been regarded as an appreciable device for topical administration without inducing side effects, and they are painless and do not cause bleeding. In this study, an MN patch with controlled transdermal dual-drug release was developed to achieve combinatory treatment of keloid scars using a heterogeneous gelatin-structured composite MN. Gelatin hydrogel was used as a substrate to load gallic acid (GA) and quercetin-loaded amphiphilic gelatin nanoparticles to fabricate dual-drug heterogeneous composite MNs. The results of the insertion test and mechanical properties of the MNs showed that the heterogeneous composite MN patches could be self-pressed into the stratum corneum and control dual-drug release at different time periods. GA was released at an earlier stage to retard the proliferation of fibroblasts, and quercetin was released at a later stage as a strong antioxidant to erase the generation of reactive oxygen species. Furthermore, real-time quantitative polymerase chain reaction data indicated that the gene expression of fibroblasts (such as Col I and III) was downregulated in the dual-drug system. The above results demonstrate that using heterogeneous composite MNs with the combination of dual-drug pharmacology is beneficial for preventing keloid scar formation. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a globally occurring articular cartilage degeneration disease that adversely affects both the physical and mental well-being of the patient, including limited mobility. One major pathological characteristic of OA is primarily related to articular cartilage defects resulting from abrasion and catabolic and proinflammatory mediators in OA joints. Although cell therapy has hitherto been regarded as a promising treatment for OA, the therapeutic effects did not meet expectations due to the outflow of implanted cells. Here, we aimed to explore the repair effect of magnetized chondrocytes using magnetic amphiphilic-gelatin nanocarrier (MAGNC) to enhance cellular anchored efficiency and cellular magnetic guidance (MG) toward the superficial zone of damaged cartilage. The results of in vitro experiments showed that magnetized chondrocytes could be rapidly guided along the magnetic force line to form cellular amassment. Furthermore, the Arg-Gly-Asp (RGD) motif of gelatin in MAGNC could integrate the interaction among cells to form cellular stacking. In addition, MAGNCs upregulated the gene expression of collagen II (Col II), aggrecan, and downregulated that of collagen I (Col I) to reduce cell dedifferentiation. In animal models, the magnetized chondrocytes can be guided into the superficial zone with the interaction between the internal magnetic field and MAGNC to form cellular stacking. In vivo results showed that the intensity of N-sulfated-glycosaminoglycans (sGAG) and Col II in the group of magnetized cells with magnetic guiding was higher than that in the other groups. Furthermore, smooth closure of OA cartilage defects was observed in the superficial zone after 8 weeks of implantation. The study revealed the significant potential of MAGNC in promoting the high-density stacking of chondrocytes into the cartilage surface and retaining the biological functions of implanted chondrocytes for OA cartilage repair. [ABSTRACT FROM AUTHOR]

In recent years, with the rise of global diabetes, a growing number of subjects are suffering from pain and infections caused by the invasive nature of mainstream commercial glucose meters. Non-invasive blood glucose monitoring technology has become an international research topic and a new method which could bring relief to a vast number of patients. This paper reviews the research progress and major challenges of non-invasive blood glucose detection technology in recent years, and divides it into three categories: optics, microwave and electrochemistry, based on the detection principle. The technology covers medical, materials, optics, electromagnetic wave, chemistry, biology, computational science and other related fields. The advantages and limitations of non-invasive and invasive technologies as well as electrochemistry and optics in non-invasives are compared horizontally in this paper. In addition, the current research achievements and limitations of non-invasive electrochemical glucose sensing systems in continuous monitoring, point-of-care and clinical settings are highlighted, so as to discuss the development tendency in future research. With the rapid development of wearable technology and transdermal biosensors, non-invasive blood glucose monitoring will become more efficient, affordable, robust, and more competitive on the market. [ABSTRACT FROM AUTHOR]

This study focuses on preparation and valuation of the biodegradable, native, and modified gelatin film as screen-printing substrates. Modified gelatin film was prepared by crosslinking with various crosslinking agents and the electrode array was designed by screen-printing. It was observed that the swelling ratio of C-2, crosslinked with glutaraldehyde and EDC/NHS (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide) was found to be lower (3.98%) than that of C-1 (crosslinked with only glutaraldehyde) (8.77%) and C-0 (without crosslinking) (28.15%). The obtained results indicate that the swelling ratios of both C-1 and C-2 were found to be lower than that of C-0 (control one without crosslinking). The Young's modulus for C-1 and C-2 was found to be 8.55 ± 0.57 and 23.72 ± 2.04 kPa, respectively. Hence, it was conveyed that the mechanical strength of C-2 was found to be two times higher than that of C-l, suggesting that the mechanical strength was enhanced upon dual crosslinking in this study also. The adhesion study indicates that silver ink adhesion on the gelation surface is better than that of carbon ink. In addition, the electrical response of C-2 with a screen-printed electrode (SPE) was found to be the same as the commercial polycarbonate (PC) substrate. The result of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay suggested that the silver SPE on C-2 was non-cytotoxic toward L929 fibroblast cells proliferation. The results indicated that C-2 gelatin is a promising material to act as a screen-printing substrate with excellent biodegradable and biocompatible properties. [ABSTRACT FROM AUTHOR]

Articular cartilage defect is a common disorder caused by sustained mechanical stress. Owing to its nature of avascular, cartilage had less reconstruction ability so there is always a need for other repair strategies. In this study, we proposed tissue-mimetic pellets composed of chondrocytes and hyaluronic acid-graft-amphiphilic gelatin microcapsules (HA-AGMCs) to serve as biomimetic chondrocyte extracellular matrix (ECM) environments. The multifunctional HA-AGMC with specific targeting on CD44 receptors provides excellent structural stability and demonstrates high cell viability even in the center of pellets after 14 days culture. Furthermore, with superparamagnetic iron oxide nanoparticles (SPIOs) in the microcapsule shell of HA-AGMCs, it not only showed sound cell guiding ability but also induced two physical stimulations of static magnetic field(S) and magnet-derived shear stress (MF) on chondrogenic regeneration. Cartilage tissue-specific gene expressions of Col II and SOX9 were upregulated in the present of HA-AGMC in the early stage, and HA-AGMC+MF+S held the highest chondrogenic commitments throughout the study. Additionally, cartilage tissue-mimetic pellets with magnetic stimulation can stimulate chondrogenesis and sGAG synthesis. [ABSTRACT FROM AUTHOR]

Current methods for diagnosing early stage osteoarthritis (OA) based on the magnetic resonance imaging and enzyme-linked immunosorbent assay methods are specific, but require specialized laboratory facilities and highly trained personal to obtain a definitive result. In this work, a user friendly and non-invasive quartz crystal microbalance (QCM) immunosensor method has been developed to detect Cartilage Oligomeric Matrix Protein (COMP) for early stage OA diagnosis. This QCM immunosensor was fabricated to immobilize COMP antibodies utilizing the self-assembled monolayer technique. The surface properties of the immunosensor were characterized by its FTIR and electrochemical impedance spectra (EIS). The feasibility study was based on urine samples obtained from 41 volunteers. Experiments were carried out in a flow system and the reproducibility of the electrodes was evaluated by the impedance measured by EIS. Its potential dynamically monitored the immunoreaction processes and could increase the efficiency and sensitivity of COMP detection in laboratory-cultured preparations and clinical samples. The frequency responses of the QCM immunosensor changed from 6 kHz when testing 50 ng/mL COMP concentration. The linear regression equation of frequency shift and COMP concentration was determined as: y=0.0872 x+1.2138 (R2=0.9957). The COMP in urine was also determined by both QCM and EIS for comparison. A highly sensitive, user friendly and cost effective analytical method for the early stage OA diagnosis has thus been successfully developed.